1. Field of the Invention
The present invention relates to an electrical connector assembly for electrically connecting an electronic package, such as an integrated circuit (IC), package with a circuit substrate, such as a printed circuit board (PCB), and particularly to an electrical connector assembly with a pick up cap, which has concaved portions for bearing external pressing forces.
2. Description of the Related Art
Land grid array (LGA) connector assembly for electrically connecting a land grid package (LGP) with a printed circuit board (PCB) is widely used. In an automatic assembly process, the LGA connector assembly can be accurately and rapidly assembled to a predetermined position on a PCB by means of a vacuum-suction device.
FIG. 1 illustrates a conventional LGA connector assembly 100′ that is capable of being moved by a vacuum-suction device (not shown), and the LGA connector assembly 100′ includes a socket body, a pick up cap 2′ mounted on the socket body, and a fixing mechanism disposed around the socket body. The fixing mechanism includes a stiffener 12′, a top cover 14′ connected pivotally to a first end of the stiffener 12′ and having a central opening 141′, and an L-shaped load lever 15′ mounted pivotally on a second end of the stiffener 12′ opposite to the first end. The top cover 14′ has an engaging tongue 142′ that is operable so as to be pressed by a bent central section 151′ of the load lever 15′ and two opposite pressing portions 143′ offset downwardly. The socket body includes an insulative housing 11′ and a plurality of terminals 13′ received in the insulative housing 11′. The insulating housing 11′ is mounted in the stiffener 12′ and has a receiving cavity 111′ for accommodating an LGP (not shown). The pick up cap 2′ is disposed within the receiving cavity 111′ of the insulating housing 11′, and can be sucked by a vacuum-suction nozzle of the vacuum suction device (not shown). The pick up cap 2′ has a planar body 20′, and a plurality of positioning protrusions 21′ extending outwardly from a periphery of the planar body 20′ and engaged respectively in corresponding positioning grooves 114′ in the insulating housing 11′, such that the pick up cap 2′ is positioned relative to the insulating housing 11′. When the top cover 14′ is operated to a close position, the two pressing portions 143′ of the top cover 14′ abuts against the pick up cap 2′.
Further, two gaps 24′ may be provided in the planar body 20′ of the pick up cap 2′ between two positioning protrusions 21′ and extending along peripheral edges of the pick up cap 2′. The gaps 24′ avoid interference between the pressing portions 143′ of the top cover 14′ and the pick up cap 2′, and can also serve as ventilation openings and may improve the air flow into the insulative housing 11′ when the pick up cap 2′ is coupled to insulative housing 11′.
However, in the above-mentioned LGA connector assembly 100′, due to the two gaps 24′, the receiving cavity 111′ of the insulative housing 11′ can't be covered completely when the top cover 14′ is in the close position. In this case, some of the terminals 13′ received in the insulative housing 11′ are exposed to external surroundings. As a result, the terminals 13′ may be contaminated by external elements, such as dust, solder, and the like.
In view of the above, a new pick up cap for use with an LGA connector assembly which overcomes the above-mentioned disadvantages is desired.